Missing Space

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Missing Space

Unread post by goubda » Mon Aug 05, 2013 9:13 am


I have a DS2413+. Ever since I have had it, I seem to be missing some space. I have 6 x 2TB drives and 4 x 500GB Drives.

In theory once I have lost raid and some small overhead for the OS, I believe I should have about 10.4TB of usable space, however I only have 9.3TB so I'm missing about 1.1 TB.

So recently I did some digging and notices that there is a Raid 5 group MD2 made up of 500GB disks and 500GB off the 2TB drives. There are 10 disks in the Raid group, however 3 of them appear to be marked as spare. Missing space!!

If I fail a drive by pulling it out, immediately it uses one of the spares to rebuild that raid group and fails the others raid groups. Re-adding the Disk repairs the other raid groups and re-adds the spare to MD2

Does anyone know why this may be the case and if there is a way to activate the spares.
Maybe - mdadm --grow /dev/md2 -n 10

FYI - /proc/mdstat results

Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md3 : active raid5 sdj6[7] sdb6[3] sdc6[4] sdd6[5] sda6[6] sde6[1]
7325593920 blocks super 1.2 level 5, 64k chunk, algorithm 2 [6/6] [UUUUUU]

md2 : active raid5 sdf5[12](S) sdh5[0] sdj5[11] sdb5[7](S) sda5[10](S) sdc5[8] sde5[4] sdd5[9] sdi5[3] sdg5[1]
2901909888 blocks super 1.2 level 5, 64k chunk, algorithm 2 [7/7] [UUUUUUU]
bitmap: 0/4 pages [0KB], 65536KB chunk

md1 : active raid1 sdf2[3] sda2[9] sdb2[7] sdc2[8] sdd2[6] sde2[5] sdg2[0] sdh2[1] sdi2[4] sdj2[2]
2097088 blocks [12/10] [UUUUUUUUUU__]
bitmap: 1/1 pages [4KB], 65536KB chunk

md0 : active raid1 sdf1[3] sda1[9] sdb1[7] sdc1[8] sdd1[6] sde1[5] sdg1[0] sdh1[1] sdi1[4] sdj1[2]
2490176 blocks [12/10] [UUUUUUUUUU__]
bitmap: 1/1 pages [4KB], 65536KB chunk

unused devices: <none>

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